server-info: clean up after writing info/packs

We allocate pack information in a static global list but
never clean it up. This leaks memory, and means that calling
update_server_info twice will generate a buggy file (it will
have duplicate entries).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/server-info.c b/server-info.c
index d54a3d6..31f4a74 100644
--- a/server-info.c
+++ b/server-info.c
@@ -233,6 +233,14 @@
 		info[i]->new_num = i;
 }
 
+static void free_pack_info(void)
+{
+	int i;
+	for (i = 0; i < num_pack; i++)
+		free(info[i]);
+	free(info);
+}
+
 static int write_pack_info_file(FILE *fp)
 {
 	int i;
@@ -252,6 +260,7 @@
 
 	init_pack_info(infofile, force);
 	ret = update_info_file(infofile, write_pack_info_file);
+	free_pack_info();
 	free(infofile);
 	return ret;
 }